Oil and gas producers typically image subterranean rock layers to determine the location and shape of the subterranean rock layers. Such imaging may also be used to identify a boundary between the subterranean rock layer and an adjacent subterranean rock layer. The imaging is often performed using an imaging tool disposed within a borehole drilled into the subterranean rock layer to be imaged.
Identifying a boundary of a subterranean rock layer is an important aspect of oil or gas well production. For example, identifying such a boundary of a rock layer enables oil or gas producers to plan well locations to efficiently and optimally extract oil or gas. Additionally, knowing the boundary of a rock layer may prevent oil and gas producers from drilling into undesired rock layers.
Currently, subterranean rock layer boundaries are imaged and/or measured by time-indexed waveforms or signals that are emitted by a transmitter and received by sensors or receivers. These receivers are located a distance away from the transmitter in a borehole. Typically, the transmitter(s) may be located on the surface while the receivers are located in a borehole. The signal emitted from the transmitter(s) propagates through the rock layer being logged, reflects and/or refracts off of a boundary of the rock layer, and is received by the receivers. The waveforms or signals received by the receivers may be processed using signal migration to determine the distance between the receivers in the borehole and the rock layer boundary. However, the velocity of the waveforms or signals may be affected by anisotropic properties in the logged rock layer or boundary such as faults in the rock layer, cracks in the rock layer, a change in lithology in the rock layer or a change in an unconformity within the rock layer.